In order to obtain maximum yield from each tobacco plant, it is necessary to remove the flowering top portions of each plant at an appropriate time during the plant's growth period, to prevent vital nutrients necessary for the growth of the tobacco leaves from being detoured to the flowering top portions. At first, the removal of the flowering portions was accomplished by manual labour, the labourers moving down each row parting the upper leaves of each plant, and severing the flowering portions, depositing them in the openings between adjacent rows of tobacco plants. However, this method was not satisfactory, due in part to the time and cost factor, but more importantly, due to the unavailability of skilled labor in performing the topping operation.
More recently, machines and apparatus have been developed to replace the manual labor. One such machine is disclosed in U.S. Pat. No. 3,482,379 wherein a tobacco topping machine is disclosed, which pushes the top leaves down and away from the cutting mechanism, grasps the stalk firmly and passes it through a cutting mechanism thereby severing the flower portion from the plant, applies a sucker control chemical to the plant just below the cut portion, and removes the severed flowering portion of the stalk to an area between the crops rows. In U.S. Pat. No. 3,695,013 a tobacco topping apparatus is disclosed which utilizes a power operated blower for establishing a flow of air generally downwardly onto the tobacco plant, to deflect the leaves downwardly and expose the flower portion, an inclined rotating cutting blade to cut the flower portion of each plant into small particles without cutting the top leaves by virtue of the leaves having been deflected downwardly by the flow of air, and impart a motion thereto, and a peripheral wall surrounding the inclined blade to confine the movement of the small particles to a predetermined path for deposition between the rows of the tobacco plants.
However, no structure to date has provided a completely satisfactory tobacco apparatus.
While the structure of U.S. Pat. No. 3,482,379 recognizes the problems which arise from the deposition of the cut flower portions onto the plant leaves--the deposition prevents the covered portions of the plant leaves from absorbing the necessary sunshine for development resulting in discolouration and rejection for marketing purposes--still cut flower portions of the plant were deposited on the leaves due to the nature of the means used to convey the flowering portions away from the plant. Furthermore, due to the nature of the conveyors and the means used to depress the tobacco leaves, breakage of the upper leaves was not an uncommon occurrence.
Insofar as the structure disclosed in U.S. Pat. No. 3,695,013 is concerned, due to the nature of such structure, not all of the upper leaves are deflected and maintained out of contact with the cutting blade during the cutting operation. As a result, during the cutting operation, the upper leaves are cut or mangled. Furthermore, the method of cutting the flowering portion into smaller particles, disclosed in such patent, splinters the stalk of the plant, thereby damaging the plant to the extent that further growth and development of the plant is impeded.
A further difficulty arises in severing the flower portion of the tobacco plant for which no adequate provision has been made in the prior art structures. The leaves of a tobacco plant generally behave differently at various times at of the day and during different weather conditions. For example, in the morning, the leaves of the plant are usually stiffer and closer around the flowering portion, due in part to the cooler night air, then during the latter part of the day, when there is considerable sunshine and heat, with the result that the leaves tend to open away from the stalk and flower portion more, thereby exposing the flower portion more to the sunlight. As a result of the above differences, more force is necessary to deflect the leaves to expose the flower portion for cutting in the morning, than late in the afternoon on a hot day.
It is therfore, an object of this invention, to provide a tobacco topping apparatus which effectively positions the upper leaves of the plant adjacent the flower portion, out of contact with the cutting means during the cutting operation.
It is a further object of this invention to provide a tobacco topping apparatus to carry out the cutting operation, with minimal effect on the plant.
It is still a further object of this invention to provide a tobacco topping apparatus which is adjustable to permit effective use at various times of the day and during different weather conditions.
Further and other objects, features and advantages of the invention will be realized by those skilled in the art from the following summary of the invention and detailed description of a preferred embodiment thereof.